In the anime

Sparks of yellow electricity appear in between Galvantula's pedipalps and it fires it as a stream of yellow electricity into the air. As it flies through the air, the tip opens up and expands, forming into a large spider web of electricity. The web then covers over the opponent and electrocutes it.

Sparks of yellow electricity appear in between Joltik's mandibles and it fires it as a stream of yellow electricity into the air. As it flies through the air, the tip opens up and expands, forming into a large spider web of electricity. The web then covers over the opponent and electrocutes it.